I. Field of the Invention
The present invention relates generally to the field of song bird feeders and, more particularly, to bird feeders which prevent unwanted animals, rodents and birds from feeding at the feeder. The feeder of the present invention also provides a great deal of amusement to those watching when an unwanted rodent alights on the feeder.
Bird watching is a fulfilling activity for many and provides an educational tool for children in that it increases environmental consciousness. Further, bird feeders assist certain species of birds to find foods and supplements to augment their diets, especially during periods of severe weather.
II. Description of the Related Art
Not only are there many bird feeders of unlimited designs, there are also bird feeders which have been designed to prevent unwanted animals, rodents and birds from invading and eating from bird feeders which have been designed for the typical lightweight song bird.
The prior art has disclosed many devices which offer discouragement or removal of unwanted pests at the song bird feeder. For instance, there are a great number of known bird feeders which have weight sensitive, tiltable perches for dislodging the unwanted pest, such as shown in the patents to Loken (U.S. Pat. No. 5,105,765), Wessner (U.S. Pat. No. 5,048,461) and Dehls (U.S. Pat. No. 4,541,362).
There are many electrical type devices which will shock unwanted pests which alight on a song bird feeder, such as is shown in Fry (U.S. Pat. No. 5,392,732) and Collins (U.S. Pat. No. 5,471,951).
Many weight sensitive devices have been shown wherein the food openings in the bird feeder will close if an animal heavier than the normal song bird, sits on the perch near the food opening. The patent to Drakos (U.S. Pat. No. 5,720,238) is typical of this type of mechanism.
There are also devices which sense an animal, such as a squirrel or heavy unwanted bird, which will, at a predetermined point in time, effectively remove the unwanted pest from the feeder. Typical of these prior devices, is the patent to Hibbard (U.S. Pat. No. 5,297,503) and Korb (U.S. Pat. No. 5,690,056). It is this latter type of bird feeder to which the present invention pertains.